Systems for transporting articles such as FOUPs using traveling vehicles such as overhead traveling vehicles are used in semiconductor factories or the like. In such a system, it is required to maintain the high utilization ratio of the entire system. For this purpose, it is required to not only simply transport articles but also provide preventive maintenance for the traveling vehicles of the system and equipment on the ground such as travel rails. In this specification, equipment provided on the ground such as travel rails, equipment associated with the travel rails such as non-contact power feeder line, load ports, buffers as temporal storages of the articles are referred to as the “infrastructure” of the traveling vehicle system.
With regard to self-diagnosis of the traveling vehicle system, according to the disclosure of Patent Publication 1 (JP4117625C), occurrence of abnormal vibrations or the like is reported from a traveling vehicle to a system controller.
If any abnormal condition occurs again in another traveling vehicle at the same position on the travel rail, it is determined that the abnormal condition is caused on the infrastructure side. If any abnormal condition occurs again in the same traveling vehicle at another position on the travel rail, it is determined that the abnormal condition is caused on the traveling vehicle side. The inventor studied to perform self-diagnosis of the system more properly for making it possible to provide preventive maintenance, and arrived at the present invention.